Dementia is a loss or deficit of higher intelligence and has a variety of clinical manifestations: 1) memory loss, which is the most common manifestation; 2) personality change, from rule-abiding to unruly or moral loss; 3) sudden loss of interest in one’s hobbies and interests; 4) language impairment and inability to express oneself normally; 5) psychiatric symptoms may complicate patients with intermediate or advanced dementia; 6) patients with advanced dementia may have symptoms such as muscle tonus and bed rest.